If you're ready for a nap by midafternoon, you're not alone. One out of every two women report the energy drain that descends after lunch. Next time, try a quick, easy workout instead of coffee.

"Exercise gives you instant pep with no post caffeine or sugar crash," says Kelli Calabrese, personal trainer and American Council on Exercise spokesperson. Increased bloodflow also helps clear your head, and the release of pleasure chemicals, such as serotonin, improves your mood.